1. Field of the Invention
This invention generally relates to a cable operating mechanism. More specifically, the present invention relates to a cable operating mechanism for a cable operated bicycle shifter that operates a rear derailleur.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle.
One part of the bicycle that has been extensively redesigned is the bicycle transmission. Specifically, a bicycle transmission typically includes front and rear shift operating devices designed to operate front and rear derailleurs to move the derailleurs laterally over a plurality of sprockets or gears. The sprockets or gears are usually coupled to the front crank and the rear wheel such that a pedaling force from the rider is transferred to the rear wheel via the chain.
In the case of a rear derailleur, usually, the rear derailleur is configured to be able to shift the chain between many gears as compared with a front derailleur. A typical rear derailleur basically includes a base member, a pair of link members and a movable member with a chain guide. The chain guide is typically pivotally mounted to the movable member. The chain guide typically has a chain cage with a guide pulley and a tension pulley. The link members are pivotally coupled between the base member and the movable member to form a four bar parallelogram linkage. A shift cable is coupled between the base member and one of the link members to move the chain guide laterally with respect to the center plane of the bicycle. Thus, an inner wire of the cable is pulled to move the chain guide in a first lateral direction with respect to the center plane of the bicycle, and released to move the chain guide in a second lateral direction with respect to the center plane of the bicycle.
With this type of rear derailleur, a larger amount of displacement of the inner wire of the shift cable is required for shifting to and from the two end shift positions than for shifting to and from the middle shift positions. Thus, the rider typically must move a shift operating device more for shifting to and from the two end shift positions than for shifting to and from the middle shift positions.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved cable operating mechanism. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.